The present invention is generally directed to an illuminated traffic sign and, more specifically, to an illuminated traffic sign that includes vehicle sensing capabilities.
Traffic signs have been utilized in various locations, e.g., at road intersections, road curves, along roads and at railroad crossings, to alert drivers of motor vehicles to various road hazards and applicable traffic regulations. A number of designers have incorporated one or more light sources within traffic signs and have incorporated traffic signs on certain motor vehicles, e.g., school buses. U.S. Pat. No. 5,635,902 discloses a school bus stop sign that is rotatably coupled to a school bus. The bus stop sign includes an array of light emitting diodes (LEDs) disposed on the stop sign to provide illumination. An associated flashing or pulsing circuit is utilized in conjunction with the LEDs, which may be arranged on a sign to define a word, such as “stop,” and may be arranged on both sides of the bus stop sign. The pulsing circuit periodically provides current to the LEDs, which causes them to flash, enhancing the visibility of the bus stop sign to drivers of nearby vehicles and/or children entering and exiting the associated school bus.
U.S. Pat. No. 6,222,462 is directed to an apparatus for warning drivers of the presence of a concealed hazard, such as a concealed school bus stopping location. The apparatus includes a sign, adapted for installation along a highway, with associated warning lights and a receiver. The warning lights are periodically illuminated when the sign is in a warning mode, which occurs when the receiver receives a warning signal from a transmitter that may be located within a school bus. The receiver is electronically connected to electronic circuitry that includes a switch, which flashes the warning lights. In a disclosed embodiment, the warning lights include an LED array. In another disclosed embodiment, a solar panel provides power to recharge a rechargeable battery, which powers the receiver, warning lights and associated electronic circuitry.
U.S. Pat. No. 5,935,190 is directed to a traffic monitoring system that includes a Doppler radar transceiver, a video camera and a digital computer for processing a Doppler signal. The system also includes a video cassette recorder (VCR), a high-speed camera and a laptop computer for downloading control settings and a program from a diskette or memory card to the computer. The system automatically measures the speeds of vehicles, photographs vehicles that exceed a specified speed limit and records prevailing traffic conditions onto a video tape installed within the VCR. The Doppler radar transceiver generates a Doppler signal having a pair of channels. The phase of one channel, with respect to the other channel, provides an indication of whether a vehicle is approaching or receding from the Doppler radar transceiver.
As stated above, traffic signs, e.g., stop signs, speed limit signs, yield signs and railroad crossing signs, are widely utilized to alert a driver of a motor vehicle and to instruct a driver of a motor vehicle to take an appropriate action. However, in many cases, a traffic sign may be concealed from view due to an obstruction, such as tall vegetation, walls, buildings, billboards, a hill and/or a curve in a road. Further, drivers that are unfamiliar with a given area may fail to see a traffic sign, even when unobstructed, and, thus, fail to respond appropriately. As one particular example, the inventor's son was nearly killed and the vehicle he was driving was totaled when a young driver in a small pickup truck ran a stop sign at 55 mph and hit the vehicle in the lower section of the driver's door. The intersection was a two-way stop and the inventor's son was on a through road with no stop sign. The intersection offered no view of the orthogonal road approaching the intersection. In this case, the young driver was distracted and failed to observe a plainly visible stop sign. Such observation failures may be relatively frequent on country roads on the outskirts of populated areas, as any driver can become preoccupied or fail to notice a roadside warning sign with tragic results.
What is needed is a traffic sign that alerts a driver of a motor vehicle to the traffic sign such that the driver of the motor vehicle can take an appropriate action.